HI I have a 3 yr old Chocolate lab female and I am wanting to breed her once she is an amzing dog and we are very resposible people. But anyways my question is her last heat cycle was 4 months ago and she only spotted a spot of blood for one day and it was it was only a spot here and there. This time thereh as been no blood as far as I know as I am home all day everyday. We put her with a male and he went nuts and she stood there but they did not lock after an hour so could it be possible that she is not in the right stage of her heat for them to lock as the male is experienced. anmy help would be great thanks